A command value for automatically performing acceleration/deceleration that is coordinated with steering operations is disclosed, for example, in Non-Patent Document 1 ((Eq. 1)).
                    [                  Eq          .                                          ⁢          1                ]                                                                      G          xc                =                                            -                              sgn                ⁡                                  (                                                            G                      y                                        ·                                                                  G                        .                                            y                                                        )                                                      ⁢                                          C                xy                                            1                +                Ts                                      ⁢                                                                          G                  .                                y                                                            +                                    G              x_DC                        ⁢                                                  (                                                          ⁢                                                                  ⁢                                  G                  y                                            =                                                G                  .                                y_dot                                      )                                              (                  Eq          .                                          ⁢          1                )            
This is basically a simple control rule where lateral jerk Gy—dot is multiplied by gain Cxy, and a value to which a first-order lag is imparted is taken to be longitudinal acceleration/deceleration control command Gxc (equivalent to target longitudinal acceleration/deceleration control command (Gxt)). It is confirmed in Non-Patent Document 2 that an expert driver's coordinated control strategy for lateral and longitudinal motions may thus be partially simulated. Gx—DC in the equation above is a deceleration component that is not coordinated with lateral motion. It is a term that is required in cases where there is anticipatory deceleration when a corner is ahead or where there is a zone speed command. Further, the sgn (signum) term is a term provided so that the operation above may be attained with respect to both right corners and left corners. Specifically, an operation may be attained where deceleration is performed at turn-in upon starting steering, deceleration is suspended once at steady turn (since lateral jerk becomes zero), and acceleration is performed upon starting to ease steering when exiting the corner.
When thus controlled, with respect to a diagram in which the horizontal axis represents the longitudinal acceleration of a vehicle and the vertical axis the lateral acceleration of the vehicle, the combined acceleration (denoted by G) of longitudinal acceleration and lateral acceleration is so oriented (vectored) as to transition in a curved manner with the passage of time. It is therefore called “G-Vectoring control.”
In addition, with respect to a sideslip prevention system for improving safety performance at the critical driving region, it is reported in Non-Patent Document 3 that because it becomes unstable (divergent) when vehicle behavior transitions to a region in a phase plane for vehicle sideslip angle β and vehicle sideslip angular speed (β_dot) that is apart from the origin and where the signs of β and β_dot are the same (the first and third quadrants), it is effective when used in the determination for activating the sideslip prevention system. It is disclosed that the vehicle is stabilized by applying different brake hydraulic pressures on the left and right wheels based on sideslip information, generating decelerating forces that differ between the left and the right, and generating a yaw moment in a direction in which the sideslip angle becomes smaller.    Non-Patent Document 1: M. Yamakado, M. Abe. Improvement of Vehicle Agility and Stability by G-Vectoring Control, Proc. of AVEC2008-080420.    Non-Patent Document 2: M. Yamakado, M. Abe: Proposal of the longitudinal driver model in coordination with vehicle lateral motion based upon jerk information, Review of Automotive Engineering, Vol. 29. No. 4. October 2008, P. 533˜541.    Non-Patent Document 3: S. Inagaki, I. Kushiro, M. Yamamoto: Analysis on Vehicle Stability in Critical Cornering Using Phase-Plane Method, Proc. of AVEC1994-9438411